(Revised) DESCRIPTION (provided by applicant): Alcohol has emerged as a critical cofactor in HIV infection. Yet we still lack an understanding of how in-the-moment forces - such as acute intoxication - affect a person's decision to engage in risky behaviors. Our long-term goal is to illuminate the role played by intoxication in decision-making related to infectious diseases. Perhaps there exist heretofore-uninvestigated biphasic effects that would clarify paradoxical evidence of alcohol-induced suppression and associated outcomes. Such consideration may expand our understanding of alcohol and risky outcomes. The specific aims are (1) to examine the linkages among alcohol and risky behavior; (2) to evaluate the viability of the alcohol myopia model for explaining postdrinking attitudes and behavior; (3) to investigate alcohol impairment of behavior control; and (4) to expand the currently scant fund of experimental data about women after drinking by evaluating for systematic gender differences in these relationships for intoxication and risky behavior. To address these aims, six controlled laboratory experiments are planned systematically manipulating alcohol (alcohol, none), BAC limb (ascending, descending), dosage (moderate, high), behavioral activation (maximize, none, suppress), and conflict (high, low). The sample will be elevated-risk, unmarried men and women attending urban university campuses and/or residing in urban census tracts. The overarching hypothesis is that alcohol impairs the capacity to inhibit behavior and that it directly and indirectly (through its impairment of inhibition) impairs the capacity to inhibit risk-taking. Alcohol should interact with limb such that ascending exceeds descending impact and should interact such that alcohol fosters riskier outcomes under high conflict. In concert with personality and other factors, the data may inform key knowledge gaps, advance theory, and foster refinement of existing prevention approaches and formulation of new ones.